Dimpling and riveting machine



H. R. FISCHER DIMPLING AND RI VETING MACHINE June 8 1948.

9 Sheets-Sheet 1 Filed Feb. 15, 1945 ATTORNEY June 8, 1948.

HR. FISCHER DIMPLING AND RIVETING MACHINE INVENTOR //0mzeo )Pfix/wg BY 2 .M D? W m 2 s m z e 2 a 9 w 1 w t 5 a 8 H 8 L: n u w Q HQ... W 2 1 MH 0 W 0% 1 1 M w r M n F /9 d m e n w F a z June 8, 1948. H. R. FISCHER DIMPLING AND RIVETING MACHINE 9 Sheets-Sheet 3 Filed Feb. 15, 1945 W C R J m m? w W ATTORNEY June 8, 1948. H. R. FISCHER 2,442,949

uLMPLING AND RIVETING MACHINE Filed Feb. 15, 1945 v 9 Sheets-Sheet 4 INVENTOR /Va/r4,m K firm 4.

BY T A.

ATTORNEY June 8, 1948. H. R. FISCHER DIMPLING AND RIVETING MACHINE 9 Shets-Sheet 5 Filed Feb. 15, 1945 ""WMQ 4 3 0 6 vMM INVENTOR //0/x 4/?0 f FLY/EA.

z ATTORNEY June 8, 1948.

Filed Feb. 15', 1945 H. R. FISCHER DIMPLING AND RIVETING MACHINE 9 Sheets-Sheet June 8, 1948. H. R. FISCHER 2,442,949

DIMPLING AND RIVETING MACHINE Filed Feb. 15, 1945 9 Sheets-Sheet 7 INVENTOR ATTORNEY June 8, 1948. s 2,442,949

DIMPLING AND RIVETING MACHINE Filed Feb. .15, 1945 9 Sheets-Sheet 8 June 8, 19548. H. R. FISCHER 2,442,949

DIMPLING AND RTVETING MACHINE Filed Feb. 15., 1945 i 9 Sheets-Sheet 9 ATTORNEY Eatented June 8, 1943 DIMPLIN G AND RIVETING MACHINE Howard B. Fischer, Detroit, Mich., assignor to Chicago Pneumatic Tool Company, New York, N. Y., a corporation of New Jersey Application February 15, 1945, Serial No. 577,953

6 Claims. 1

This invention relates to dimpling and riveting machines and particularly to a type of machine adapted to dimple the work or sheet metal by means of a rivet introduced into a hole therein and thereafter to set the rivet in the dimpled portion of the work. This type of machine is especiall suited for the assembly of aluminum sheets to form the skin covering on the wings, fuselage and other exposed parts of an airplane.

The main object of the invention is to equip a dimpling and/or riveting machine with facilities for using a flush type countersunk head rivet for forming a dimple in the work by the pressure of the rivet head against the sheets.

Another object is to have such a machine equipped with instrumentalities to set the rivet in situ following the dimpling step performed by said rivet and thus insure a perfect fit of the latter in the dimpled portion of the work.

A further object is to save time and eliminate needless steps and motions usually considered conventional and necessary in dimpling and riveting operations by causing the riveting operation to follow as a later stage of the dimpling operation without in any way shifting or disturbing the Work between stages.

It is also an object to have the dimpling and riveting machine provided with means for automatically carrying out the entire operation of dimpling and subsequent riveting when the cycle of operation has once been started.

Other objects and advantages of the invention will appear more fully in the following specification when noted in conjunction with the accompanying drawings, in which:

Fig. 1 is a general perspective view of a dimpling and riveting machine equipped with apparatus embodying the invention in a practical form;

Fig. 2 is an enlarged side elevation of the main portion of the machine with parts in section while electrical equipment associated therewith is shown in diagrammatic form, the machine being disposed in its initial stage and having a rivet insel'ted in the work piece;

Fig. 3 is a further enlarged fragmentary view, chiefly in section, of the upper front portion of the machine disclosing part of the upper jaw and part of the lower jaw with the dimpling and riveting tools therein;

Fig. 4 is a fragmentary view of the upper jaw of the same machine showing the deflection switch in detail;

Fig. 5 is a transverse section of part of Fig. 3 taken on line 5-5;

Fig. 6 is an enlarged fragmentary view, chiefly in section, of the lower front portion of the machine;

Fig. 7 is a section of the lower part of Fig. 6 taken on line 1-1 therein;

Fig. 8, which is on a larger scale than that of Figs. 3-7, is a sectional view of a control valve of the machine taken on line 88 in Fig. 2, and showing the electrical solenoid device for operating the valve;

Fig. 9 is a side elevation, partly in section, of a lever associated with the valve and solenoid device of Fig. 8;

Fig. 10 is a fragmentary longitudinal section, still further enlarged, showing the dimpling tools or dies in operative relation to the work sheets at the completion of the dimpling operation;

Fig. 11 is a side elevation similar to Fig. 2 but showing the foot or pedal switch depressed, with the parts of the machine in operative position near the start of the second or dimpling stage of operation;

Fig. 12 is yet another side elevation showing the rivet pressed into the work piece to dimple the latter, the apparatus starting in the third stage of operation;

Fig. 13 is a further side elevation with the machine starting the fourth or riveting stage of operation; and

Fig. 14 is likewise a side elevation with the machine starting the fifth stage of operation and showing the rivet set in situ in the dimpled portion of the work piece prior to the release of said work piece.

In the industries dealing with the riveting of metal sheets and especially sheets of aluminum and aluminum alloys it is common practice first to dimple the sheets in a separate preliminary operation and frequently on a special machine,

and then to remove the sheets from the latter or vice versa, after which said sheets are placed on a riveting machine or a riveting apparatus applied to the work sheets (the rivet being inserted into a hole through the work sheets at some stage of the operation) and the rivet then set. In such conventional procedures time is lost in shifting the work sheets or the apparatus from one operation to the other, not to mention that much lost motion is involved without in any way improving the result.

Hence in order to avoid such disadvantages of conventional practice and particularly with the foregoing objects in view, it is now proposed to dimple work sheets by means of a rivet inserted at the beginning of the operation and finally set in a later stage of said operation without shifting the work sheets from the machine upon which the operation first started.

The machine which is preferably used for the purpose of the presentinvention is mainly that shown and described in the copending application Serial No. 514,068, filed December 13, 1943 for Compression riveter, certain modifications and additions being now included to embody the features of this invention. Thus referring again and 23, but Without straining the yoke beyond the elastic or endurance limit of the steel; Asta tionary dolly supporting sleeve 26 extends vertically through the lower. jaw 23, terminating at the upper end in a retaining flange '2lresting on said jaw and the sleeve projecting below the lower end of said jaw for a purpose which will presently appear.

The upper jaw 22 at its front end-has a correspondingly opposite plunger 28 (Fig 3) slidably mounted for movement toward or from dolly sleeve 26 in a pair of bushings 29, 30, spaced apart in bore 3| and axially alined with the dollysleeve. Plunger 28 is normally urgedupward into initial idle position by a return, spring 32 mounted on the plunger beneath collar 33 which is fixedon the latter, the spring engaging against saidcollar and resting on bushing 30.. The jawu22 extends upwardly and cooperates with a pair of transverse bolts 34 in supporting an upper-frameor superstructure 35,, the latter being preferably U- shaped in cross section and straddling the upward extension of jaw 22. The front endofframe 35 is closed by a plate 36. The rear end of the frame is bolted to a fluid drive cy1inder'3l which in turn is bolted to a control valve housing39. Within said frame 35 an operating cam lever 48 is pivoted at 4| and providedwitha nose, 42 making active contact .with .the 'upper end of the tool plunger 28 and during operation serving to depress the same to dimple-work sheets or set a rivet.

The cylinder contains a reciprocable piston 43 provided with a hollow piston rod extending slide ably through the front end wall of the cylinder, the forward end of said piston rod receiving a boss 41, Fig. 3, forming an extension upon a forked roller block 48 in which a pair of rotatable rollers 49 are mounted.,onejabove theother. The lower roller rides upon theupper approximately straight surface of, the cam lever. 40. while. the upper roller rolls along the under surface of a rail secured within thetop of the upper frame 35 by screws 52. As shown in Figs. 2; 3 and 1l-14, the rollers roll over each other, there- I by relieving the forked block of a large part of the reaction which is transmitted from the cam lever and upwardly through the rollers tothe track and. yoke. An inner piston rod 53, is screwedat itsforward end into the boss 41, of the roller block and passes through the piston,. on the rear end of which it has an increased di-. ameter portion surrounded by a sleeve54retained in association therewith by a nut 55, screwedpn the rear end of saidrod. Thus if the piston is in a rearward position the rollerblock will also occupy w d thd awn po t i w ic the lower roller engagesina recessed portion 56 of the cam lever nearthe pivot!" thereof'which allows the spring urged plunger 28 to risesand thereby swing the cam lever upward to a high inclined position about its pivot (Figs. 2 and 3). When the roller block is forced forward, by the forward travel of the piston upon the latter being driven by pressure fluid entering cylinder 31, the rollers. engaging against rail5l andcamlever will obviously swing the Iatter downprogressively and thereby cause the tool plunger to descend. The upper surface of the cam lever 40 is so sh ape d that the lever and plunger 28 are moved first rapidly and then more slowly but with a; substantially uniform mechanical advantage or-speed ratiobetween piston 43 and plunger In order to.a ctuate.the piston as just indicated and thereby the cam lever and plunger, a pressurefluid port 51 in the rear wall 58 of the cylinder (Fig. 8) is arranged to receive pressure fluid from a passage 59 in valve housing 39 under control of a valve 6|, the fluid being introduced into the machine through a fixture 62 (Fig. 1) from a flexible tube or hose line 63 which is connected to an appropriate source of pressure fluid.- From the entrance fixture 62 the pressure fluid passes through an air line oiler. 64 and apressureregulator 65 controlled by a regulating screw 66,- past the pressure gauge 61 and thence up through a hose line 68 to the valve housing39. Within the latter the valve 6|. (Fig. 8) has two-spaced pairs of valve heads 69,11 mountedon a reciprocating valve stem 12, and providing four individual seating type valves, mounted-in pairs, back-to-back. Valve heads BQ-and 'H consist of soft rubber discs each of which is perforated to fit and closely surround thevalve stem 12.

rated by a spacer sleeve 13.. The lower disc ll seats against a shoulder HI onthe valve stem. Near its lower end the valve stem has a cylindrical portion-slidable in a bushing'lB firmly fixedlower end by; internally threaded ring 8 I- screwed: on the sleeve and fitted into a counterbore in the valve housing-ring 8i serving-to retain. the inner ring 83 as well asappropriate-packing 84 above and below the same incompressed con-.

dition to prevent leakage above sleeve T1.

In the upper portion of-valve housing 39a sleeve B5;is secured by ;screaw threads and is locked in position in: thehousing, bya lock :nut

81,, An upper section 8& of the valve stemmis;

slidably supported in sleeve 85. Section 88 screws on to the upper end .of stem section'l2and. engages the upper face ofurubber disc 59.1130. hold all four discs under adjustable.axialcompressions Sleeve, 85.:has a valve.seat.89. at .its lowerend adapted to be engaged bytheupper surfaceof valve head 69 in raisedposition of. the-valve. Between the two valve headsis located. a valve seat bushing 9| .held rigidly inan intermediate. bore in .thevalvehousing, this bushing-having an upper valve seat 93 engaged bythe lowerv surface of valve head 69 and a lower valveseat 94 adapted to be engaged by the upper face of the other valve head H in-raised position of the It is thus evident that valve head fill-isvalve. movable from valve seat 89'to seat 93 while valve head H is correspondingly movable therewith between valve seats 94 and .19. Between the seats 93 and 94- is an annular connecting passage-'91 alternately closed by valve head 69 or by head H, while a port 98 opening into said passage 91 The .discs-in each pair abut each other while the pairs or heads are sepa-.

communicates with the front end of the cylinder The previously mentioned passage 59 communicates through a series of ports in sleeve 85 with an upper annular valve passage I02, said passage 59 and passage I62 connecting with a passage I23 which extends down in the valve housing along one side toward the lower end thereof and communicates through ports I04 in the sleeve TI and ring 83 with a lower annular valve chamber I25. Adjacent the upper valve head 69 is a passage I06 leading to exhaust. Adjacent the lower valve head II is a port I08 constantly supplied with live air by hose lines 63 and 6B and suitable air connections (not shown).

The control valve BI is raised and lowered in response to an electro-magnetic coil device or solenoid III. The solenoid is supported on a frame H2 which is mounted on control valve housing 39 and secured thereto by bolts I I3 (one being shown). The solenoid comprises a core I I 4 (Fig. 2) reciprocating in a coil I I5 rigidly mounted upon frame H2 and connected to a terminal box H5.

The upper valve stem 88 is screw-threaded for the reception of two spaced adjusting nuts II!- and H8. Above nut IE3, the sides of valve stem 88 are flattened to fit a rectangular slot H9 milled in a lever I2I (see Figs. 2, 8 and 9). The rear end of the lever has a hole I22 cooperating with a pivotal support on frame H2. The front end has a forked portion I23 engaging a horizontal pin carried by solenoid core II I whereby the reciprocating movement of the core causes the lever to rock about its pivot. Lever I2I seats on adjusting nut H8 and is held in contact therewith by a compression spring I2 3 which encircles valve stem 88 and which is interposed between the lever and the upper adjusting nut III. The two adjustment nuts and the compression spring are effective to transmit motion from the valve lever to the control valve GI. The spring I25 and nut I I1 actuate the control valve on the upward or power stroke, whereas on the return stroke the valve 5| is carried down with the lever in contact with the adjusting nut II 8. Downward movement of the valve SI is aided by a compression spring I25 surrounding the lower end of the valve stem and extending between a shoulder on sleeve member I'l and a collar I26 pinned to the valve stem. The purpose of the spring I25 is to prevent injury to the valve seats due to the inertia of the solenoid core H4 and also to obviate the necessity of close adjustments.

The plunger 25 already referred to terminates at the bottom in a tool socket I2! (Fig. 3) while a tool anchoring rod I23 extends longitudinally through the plunger to establish a detachable threaded connection with a rivet set holder I29. A rivet set I3I is secured to the latter by the set screws I32, I33. A double splined key I34 eX- tends transversely through the slotted hollow upper portion I35 of the rod with one end projecting slidably into a keyway I35 in bushing 29 in all positions of the plunger so as to allow axial movement of said plunger but preventing rota tion thereof in the bushing when the rivet set holder is screwed on to the lower end of rod I28 and also preventing the rod from rotating relatively to the plunger. A small spring pressed plunger I3'I slidably mounted in the hollow upper end I35 of rod I23 pressed upwardly against key I34 and thus resiliently urges the rod downwardly relative to the plunger 28 but allows it to rise against spring pressure in the event that an upward force is applied to this rod. The purpose of seating the rod in a resilient manner is to prevent injury to the threaded connection between the lower end of rod I28 and rivet set holder I29. Should this connection work loose and the set holder drop down from plunger 28, no damage will result for the reason that when the machine is operated the shoulder of the set holder strikes the lower extremity of said plunger 28, while the slotted upper end of rod I28 is free to slide up and down on the splined key I34, eliminating any possibility of injury to the threaded connection which might have resulted if the set holder were screwed directly to a rigid part of plunger 28.

The rivet set holder associated with the plunger as described is provided with a pad plate I38, Fig. 10, surrounding the set beneath a threaded intermediate shoulder portion I39 and surrounding part of the latter without effective engagement therewith. A resilient hold down pressure pad or cushion I lI of rubber or other resilient material is mounted beneath the plate about a second intermediate diameter portion I42. A hold down pad washer I23 is held against the pressure pad by a split retaining ring I44 slidable between portion or step I62 and an annular rib I45 (Fig. 4) on the rivet set While above pad plate I33 (Fig. 3) an adjusting collar I46 is screwed on threaded portion I39 against the plate and presses upon pad Mi and thereby holds washer I43 down against ring W5 and thus normally holds the latter down against rib I 35. In Fig. 4 the rivet set is shown completely stripped of all the cooperating parts normally associated therewith and shown in section in Figs. 3 and 10, which parts together constitute a hold down pad rivet set assembly. A second rib I I! is spaced downwardly a small distance from rib I 45 (Figs. 3, 4 and 10) so as to present a retaining groove therebetween accommodating a friction ring I28 located within an externally threaded collar I49 having a flange upon the upper end and disposed slidably upon the two ribs while engaging against retaining ring I44.

Upon the threaded collar I49 a hold down sleeve I52 is screwed with a number of shims I53 clamped between the upper end of the sleeve and the flange of collar I49. The sleeve I52 has an intermediate internal shoulder serving as a stop or seat for a flange I55 on an internal rivet centering sleeve I56 slidably mounted on the lower reduced portion of the rivet set. A cap I58 is fitted over the upper end of inner sleeve I55 (with a stack of shims therebetween) to limit upward movement of the inner sleeve by said cap I58 engaging against rib I I'I, the spring I59 disposed externally of cap I58 between the lower end of collar I49 and flange I55 being centered by said cap tending resiliently to hold internal sleeve I55 down with its flan e I55 against the shoulder on sleeve I52 while allowing said internal sleeve to be independently movable in upward direction within the mentioned limits. The lower end of the hold down sleeve I52 fits slidably upon the internal sleeve and as the threaded collar Hi9 rigid with said sleeve is also slidable on ribs I45 and MI, sleeve I52 is kept in alignment with the axis of the rivet set I3I and through collar I49 engaging against retaining ring I44 01' washer I43. Thus the hold down sleeve I52 is resiliently held in its lowest position by the hold down pad I4I, allowing the sleeve to be forcibly raised while compressing said pad, as will be referred to further on.

en-4294c Completing the hold xiown pad rivet set assembly'ofthe upper jaw-,arivet upsetting pin I15] and tubular dimpling sleeve I62 are supportedby the dolly sleeve 26in the lower jaw '23 as will nowbe-considered. A hollow adjustable spindle consisting of spindle sleeve I53 (Figs. 3 and6) screwed into dolly sleeve 28 is surmounted by a spindle cap Hi l screwed into the spindle sleeve and having a central upwardly projecting tubular portion I55 of reducedexternal diameter forming a guide upon which the tubular dimpling sleeve IE2 is slidably mounted, thelatter initiallyprojecting a distance abovetheupper end of said reduced portion IE5. Both of these members namely, reduced portionIBS and tubular 'dimpling sleeve I 52 may be adjusted in height by rotation in either direction of the spindle-sleeve L63, the latter having its thread I66 engaging with'the internal thread I61 of the dolly sleeve and below said sleeve having a knurled rin I58 fixed upon sleeve I63 by a set screw I59 by which to rotate said sleeve manually. A series of 'scale markings (not shown) ma be applied approximately at 'I 'II upon the spindle sleeve to cooperate in conventional manner with corresponding scale markings along one side of f the cut-out portion I I3 (Figs. 2 and 6). A locking screw I'M having a manuallyrotating knob I15 and threaded into a locking nut I 'IB-is adapted to release oriockthe spindle sleeve in known manner in any attained position of adjustment, at will.

The lower end oftubulardimpling sleeve I62 is flanged 'and rests upon three equidistantly spaced pins I78 (Figs, and 6) which extend slidably down through the spindle cap IM to the internal cap I19 within the spindle sleeves I63. Cap I79 rests on the upper end of slidable spring sleeve I8I which is independentlymovable relatively'to the spindle sleeve and at the lower end extends down into a trip collar- I82 to which it is-secured by a long set screw I 83. The trip collar isnorinally sustainedin its highest positionwithin the spring casing I84 by a-compression spring I185 supported on supporting cap I86 engaging thread Iil'i in the casing and'capable of being screwed'up or down in the latter for properadjustrnent of the spring by engagement of an appropriate wrench or key with lugs I88 to turn said cap. The upper end of the spring casing has an internal shoulder !89 supported by a flange I9I integral with the lower'end of spindle sleeve I83, allowing the latter to be rotated by ring I68 without also rotating the spring casing, certain means yet to be described preventing such undesired rotation. The spring casing I84 thus virtually'hangs suspended on-the lower ,end of the spindle sleeve I63 and is therefore raised or lowered therewith when ring I68 is rotated in order to adjust the sleeve.

'Within the spindle cap I64 and its central tubular extension its the previously mentioned rivet upsetting pin It! is slidably disposed, continuing down in aperture-iSfZ-past cap I19 and through the inner spring sleeve MI in whichit has an increased diameter to form the cylindrical guide portion I93 slidable within said sleeve and extending down into spring I85 within whi-ch it receives the rivet upsetting pin plunger I94 .adjustably screwed into the same. The mentioned plunger extends slidably down through the upper portion-l95 of a bottom cap-I96 screwed into the internal thread I87- of the-spring casing and located a distance below-cap IB'B. -A compression spring I91 rests on-capportion-1'95 and engages beneath locknut I98 upon the .threadedportion of plunger I 94 to resiliently support the latter and the rivet upsetting ipin :IGI vin initial raised position. Below plunger Isle. shl ftable cam slide block 199 is supported in the bottomlcap I96 andrhas an inclined camsportioniflhand a rearward projection-Z02. eXtending5 throughslot1203 in the rearcofthespring casingand connectedby a bolt 20. toaipair ofconnecting strips 12115.1'igid with the :core 206 -iof.-an.electric {solenoid device 261. The'bottom cap=I QB-is .adjustableby engaging/a wrenclror the likelwith .the small head 208 and screwingrthe :cap in thread I81 toproperposition -:to support :the camrslide block: at :a-proper level with respect to said;.solenoid:device,;the cap beingheld in-placeby; the locknut 209- onwthreaded shank ZIB-engagingagainst-end closuretplate 2i I closing'the lower-Tend of the springcasing. When once'theproper-position of the bottompcap I96 has been attained,.'further.adjustmentswill not benecessary and thus a stopplate 2 I2: is' fixed by a screw or: rivetfZ I-3 to portion I;-.of said cap in eifectiveypositiontoproject into slot 203, thus preventing rotation of this cap.

The solenoid device isprovided with a frame 2M (Fig. '7) brazed or welded to thespring casing the cam.slide-.block and solenoid being normally retained resiliently in extreme forward position by a'pair of tensionisprings-2I5. extending through slots 2H5 from lugs 2II associated with strips .285 of the core to an arcuate anchoring hook member 2 I8 located exteriorly of the cylindrical springcasing Ia84 and provided with-end hooks 2I-9 engaging with the outer-ends of said springs. -When-solenoid 201 .is'energized thecore 298 is drawn into said solenoid and simultaneously draws cam-slideblock- I99 towardthe. rear against thetensionof.- springs 2I-5 and places theefiat top 22'I of the cam-slide blockdirectly beneath. plunger I94, therebyenablingthe associated rivet .upsetting pin I-GI to act asarivet-ing dolly. When the dolly solenoid 20! is de-energized,thesprings return-:said cam slide block'to'the initial position shown in Figs. 6 and 7, thereby permitting the rivet upsetting pin toyield downwardly.

Upon the solenoid frame tWo switch housings 222,:223of a: pair of micro switchesgenerally indicated at 224, ;225-are supported one above the other (Fig. 6) The lower micro-switchi224; which is associated with the dolly slide block I99, has a swingable arm 226 pendently supported upon a lug-22lfixedupon housing 222 thereof' which lug also supports aspring 22. 8v strongly biased toward said. housing and tending to hold arm1226-in the path of a bIoekEZB-fixed by bolt 204 uponthe-uppercorestrip 205, so that when the core-isattracted rearwardly by the solenoid, the block. 229 will shift the lower end of armZZB-rearWardlY away from the switch housing. Within the latter th5d011y'SWltChi224 includes a resilient contact member 23! fixe'dat the lower end'of the housing and extending upward between two stationary contacts 232, *233 which are-spaced a limited distance apart. Contactmember 23I-is capable of alternatively making; contact'with either of said stationary contacts but is normally retained againsttcontact-2SZ. A- switch operating; plunger 234 issli'dably mounted-for limited movement in the wall1ofmicro-switch housing 222 between arm .2-2Iiand contact-member 23i and is of such length that-when. arm :226. 'is'held' in" the initial position vof'F'ig. '6iby 'the ;spring 228, the plunger holds said. contact memberaway from. contact 233 and against :cdntac't3232. 'Upon'act-uationof core-206 and rearward movement of -block: 229-with con- I sequent rearward swinging of arm 226 against the pressure of spring 228, contact member 23I assumes a position in which it makes contact with stationary contact 233 while displacing plunger 234 a limited distance rearwardly through casing 222. Return of the core to initial position as already outlined removes block 229 toward spring casing I84 and allows spring 228 to return arm 226 toward the switch housing and simultaneously causes the arm to push plunger 234 into said housing and thereby shift contact member 23I to engage with contact 232.

The upper micro-switch 225 also includes a resilient contact member 235 within housing 223, normally biased upward against the stationary contact 236 and simultaneously supporting a slidable micro-switch plunger 23l projecting vertically from the upper portion of said housing. The previously mentioned trip collar I82 has a rearwardly extending trip arm 23% rigid therewith extending rearwardly through a further casing slot 239 and carrying an adjusting screw 24!) directly overhanging plunger 23'! and adapted to depress said plunger and thereby open micro-switch 225 when the sleeves I62 and I8! are depressed by a predetermined amount. The screw I83 which fixes the trip collar I82 to the spindle sleeve I63 (Fig. 6) is long enough to extend through and secure the trip arm 238 at its inner end to the trip collar while extending through the latter into the wall of the sleeve, thus uniting the spindle sleeve, trip collar and trip arm into a rigid assembly which is movable as a unit. The purpose of the switch 225 is to discontinue the power after the rivet has been headed to a predetermined height.

A third micro-switch (Fig. 4) is also associated with the machine to form part of the operating instrumentalities thereof and will be described with the means for actuating the same. Yoke 2| which is substantially of U-shape has a deflection plate 26! (Fig. 2) of somewhat similar form disposed on one side thereof. The lower arm 242 of the deflection plate is secured at its end by screws 253 or the like to the lower jaw 23 but is spaced a small distance from the latter by a spacing block 24 3 (Figs. 2 and 6), so that the plate as a whole is held out of actual contact with the yoke. A screw 245 at the rear of the yoke serves to keep the deflection plate from swinging or bending out away from said yoke and prevents any material change in the spacing between the latter and said plate.

The upper forward end 2&6 (Fig. 4) of the deflection plate extends into a switch cover or box 24! upon the upper jaw 22 at the front of the machine (Fig. l). Conductors 24B lead from the switch cover to a relay box 249 located on the other side of yoke 2| at the rear of the machine. A cable 25I leads from an outside source of current to the relay box on the machine while multiconductor cables 252 and 253 respectively also lead to said relay box from the switches 224, 225 and from a foot switch 254 which is provided with a pedal 255.

Within the cover or box 2 5i is housed a deflection switch assembly, shown best inFig. 4, comprising an inner switch box 256. The latter supports a fixed contact 25'! and a resilient contact 258 normally biased away from contact 25? toward a slidably mounted switch plunger 259 extending into said switch box through a wall thereof, and simultaneously disposed against contact 266. Plunger 259 is capable of being pushed further into the switch box against the pressure of resilient contact 258 in order to flex the latter away from contact 266 and against fixed contact 25?. A deflection switch lever 26I is rockably molmted on a knife edge fulcrum member 262 fixed on the upper jaw 22 with the short lever arm 253 extending beneath the upper end 246 of the deflection plate and the longer arm 26% of said lever disposed adjacent to the outer end of the switch plunger. It is evident that a small downward movement of the end 246 of the deflection plate while in physical contact with arm 263 will cause the upwardly projecting longer arm 264 to rock clockwise and push plunger 259 and thereby bring contact 258 into eifective engagement with the stationary contact 251. The eilect is the same when the deflection plate remains stationary and undeformed, while the jaws 22 and 23 are expanded apart during dimpling or riveting, and as the lower forward end 242 of the plate is attached to the lower jaw 23, the upper jaw 22 will raise fulcrum member 262 while upper end 2 56 of the plate prevents short arm 263 of the lever from rising with the fulcrum member, and the lever will consequently be rocked clockwise to push the switch plunger inward and close the switch as just set forth. A tension spring 265 is connected to the upper yoke jaw at one end and at the other end to the long arm 262 of lever 26I in order to retain the shorter arm 263 in constant engagement with the upper end 226 of the deflection plate so that the lever will be directly responsive to the slightest change in the relative position of upper jaw 22 with respect to that of end 246 of said deflection plate.

In order to adjust the deflection plate switch so that the latter will operate to close the circuit thereof with the desired amount of lost motion on the part of lever 26I relative to plunger 259, the switch box with its contacts and switch plunger is mounted on a shiftable switch plate 266 pivotedat 261 on the upper jaw 22. An adjusting screw 268 is threaded into a screw block 269 secured on said jaw, the screw engaging with its inner end against the side of the upper free end of the switch plate, and a tension spring ZlI is attached to the latter and to the screw block in order to bias the switch plate toward the screw and resiliently retain the plate in contact with the screw. By turning the latter, the switch box 256 can be adjusted to a position in which the lever arm 264 is spaced the desired distance from switch plunger 259 while the shorter arm 253 is in eflective contact with arm 246 of the deflection plate in normal idle condition of the machine. The purpose of the deflection switch 256 is to terminate the dimpling stroke when the yoke jaws 22, 23 spread apart by a predetermined distance.

When a cycle of operation is followed through, a pair of metal sheets herein termed the work piece 212 is assumed to have been drilled to receive a flush type countersunk head rivet 2l3 (Figs. 2 and 3) the work piece having first been manoeuvred to register the rivet head, within the bore of internal sleeve I56 carried by the rivet set holder, to accurately align the rivet with the dimpling sleeve I62 and rivet upsetting pin I61. The work piece is then held up against hold down sleeve I52.

It has been pointed out that the electrical control apparatus of this invention includes: afoot switch 254; a solenoid III for operating the control valve'GI that supplies pressure fluid to the power cylinder 31; a deflection switch 256 which breaks one contact and makes another to terminate the dimpling stroke upon the development ofa predetermined strain on the -yoke;:a:solenoid 201 which operates a slide block I99 .to obstruct downward -movement of the "rivet .upsetting :pin I'6I, il93, thereby enabling the :pin to actias a dolly "=fr heading the rivet; .a dolly switch .224 which :breaks one contact and makes another upon :movement ofthe slide-block 19.9 to operativeposition; and a rivet height switch 225'which breaks contact and thereby terminatesithe rivetingstrokeof the piston upon a predetermined movement I of the rivet set 7 I3 I and work sheets 2l2-towardth'e rivetupsettingpin I6I. .tl'n-addition the electrical "apparatus includes: a starting relay 214 which must be energized :prior to the closing of 1 the foot switch 254 in order to start a cycle of operation; :and a :dolly relay 215 connected inlparallel withfthe dolly. solenoid 201. and energized whenever-said solenoid is :operated to condition the machinef or a :riveting. stroke.

' I :the first stage :of :operation, as illustrated'iin Fig.2, the main switch (notshown) closed, connecting the 1 terminals 216, 211 .to asource :of electro=motiverforce of,:say, llfl'voltszatififlrcycles. .The :rpedal ;255 :of foot switch 254 i is up .at this time;thereby closing a circuit fromiliveiterminal 216 through conductor::21-8,.:'normally closedoontacts 258 ..-and2.260 .of deflection switch256, :conductorsr219 andiflil, upperzand movablecohtacts of ii'ootzswitch'i 54, .anrllthenlthrough :the'winding of starting relay.l-214.to ground. Uponbeingenergized, relay 221:4 aengages'the armature .withzthe front :contact :and ithereby Jocks 'itself in energized condition tindependentlyzopthe foot switch as long :as rdeflection .switch 255 sremains :in its normal position. The :Iirst stage ends .and the second begins whentthe operator :depresses'foot .pedal :25 .to shift ithe movable -contact' thereof away TfIOIIlZbhB dipper-12nd into engagement with the lower contact associatedtherewith.

ear the start :of the second stage of operation, the parts rarerasshowns inzFig. i1 1. .Starting relay 22 14 remains energized, .as :above stated, and in. cooperation with the Ii'epressedi'foot switch; 254 completes ::a "circuit tfor: energizingtthe :valve =solenoid IH. .I'he course ofithezcircuitisiasfollowsz 4 live-terminal '21 6,"conductorl21 0 ,tdefiectionswltch 255, conductor 2219, front contact and zarmature 'of starting relay 214,. movablezan'd'lower contacts of foot :switch254, :conductor .28 I, left armature and back :contact ;of dolly'relay1215, conductor .282, and throughzthe winding of -valve solenoid I I I .toz 'groun'd. Whentthesolenoid -:I H :Joecomes energized it pulls'valvetafil upwardly'therebyreversing'the. pressure'fhiid connections to'lthe cylinder $1: andcausingrmovement .of the :piston 43 forwardly or 'tothe lefts'as 'seen.in iF'ig..11. As the piston advances it acts through the rollers 49 and cam lever- 40 I130 tdepress plunger :28 and rivet set :I'3I. Accompanyingztherrivetset in its descent care the rivet-.1213, the 'metal sheets' 212, and later the tubular .dimp'lingsleeve 4:62, the three spins -I:1 8,ocap 118, spring supported '-sleeve 18!, trip collar I82, :triprarm 238: and screw 2240, the .latter tripping tthe :rivet height switch 225 although .withoutzaffecting-.any'circuit as. it strikes the switchzplungerc231. "Shortly ithereafter the dimpling s'leeve'lfl seatszon the-spindle cap |64. Upon further downward movement the rivetset .I3 I actsthrough.rtheimstoeconicalrheadiof rivet :2-13 to dimple :the' sheetsl212 :as':shown;in1ig..:10. Iherivetupsettingpin I 6 I :moves-downwardmut of rthe path of the :rivet 1.2.8 :the :dimple .is :being formed :in the :sheet imetal. Upon .the "development of a predetermined1dimp ing;pressure,:1;he strain-.ontthe yoker2 I causesideflectionswitchfiifi 12 to .t1ip,.shifting its movable contact 258 away from stationary contact .260 and into engagement'with'the-othercontact 251, which reverses piston-:43.

.iAtlthfi-stalt'Oflthe third stage of operation, the controlpartsoccupy the positions shownin Fig. 12. 'The "tripping or the deflection .switch .256 has operated'to de-energizestarting relay 214 and to'energizeadollyrrelay215 and dolly solenoid 201. 'Thetnewlyestablished circuit'extends from terminal216 through conductor 218, contacts 258 and 251 of deflection switch'256,.conductor 283, normally 'closed contacts 232, 23I of :dolly switch 224 and then alon parallel paths through the dolly =solenoid'l'2 01and'dolly relay 215 respectively to ground. When the dolly relay 215 is energized, its right armature engages the front contact to connect'the source 216 through conductor 284 to1the conductor'283 aforementioned, thereby" continuing thesupply of current to the latter afterthe deflection switch 256 is restoredto normal. In this stage of operation the piston 43 moves to the right and theplunger 28 rises to its normal position, due'to the fact that the valve solenoid =II| is de-energized. Also during this stageithe spring supported sleeve :IBI rises and the-rivet height switch 225 is restored 'to its closed position thereby shunting dolly switch 224 to providean additionalor'independent connection "between 'conductorI284 and dolly solenoid 201. Thethird stage ends when'the doll block [99.is completely shifted into the path of the vrivet'upsetting pinIIiI, 193, at which time the 'dolly'switch'224 is operated.

The fourth stage of operation commences with the parts in the Fig. 13 position. "The piston has not returned completely to its normal or rearmost position, and'the sleeve I52 has'not broken contact with the upper face of the sheet metal 212. The dolly switch 224 in its operated position is-e'ifective to energize valve solenoid III, the circuit extending from live terminal 216 through the right armature and front contact of relay 215, conductor 284, rivet height switch 225, live terminal of dolly solenoid 201, contacts23l and 233 of dolly switch 224, conductor 282 and winding of solenoid III to ground. Dolly solenoid 201 and dolly relay 214 continue to be energized as'in the preceding .stage. The operation of the valve solenoid III is eifective to cause the piston '43 to advance, and the plunger 28 and rivet set I3I to descend, as in the case of the secondstage shown in Fig. 11. In the fourth stage, however, the rivet upsetting pin [5| is held against downward movement by the dolly slide block l99 and acts as a buck bar ordolly to head the shank end of the rivet as the latter is pressed down by the riveteset I3I. Upon a predetermined approach of-the rivet set relative to the rivet upsetting pin [51, that isafter the rivet has been headed to a predetermined height, therivet height switch 225 is operated.

As the fifth step begins, the control elements occupy thepositions shown in Fig. 14. The rivet height-switch 225 has just been opened thereby de-energizing both the solenoids 201 and III and relay 215. Thepiston'43 returns to its normal or rearward position .as in the case of the third stage. Although the operator continues to depress the pedal 255, a new cycle of operation does not begin because the starting relay 214 is deienergized. To start a new cycle the pedal 255 must first be released to energize relay 214 and then depressed .to energize the valve solenoid H l.

The .various stages of operation are shown symbolically in the following diagram:

Stage 1st 2nd 3rd 4th 5th Drawing Fig 2 11 12 13 14 Starting relay 274 E E D D D Foot switch 254 N 1 O O O O 1 Valve solenoid 1ll D E D E D Piston 43 R lVIF MR LIF MR Deflection switch 25o N N 1 O, N N N Dolly solenoid 207. D D E E D Dolly relay 275.... D D E E D Dolly switch 224 N N N l (l 0. N Rivet height switch 225. N N, 0 O N N 1 O, N

Symbols:

Eenorgized.

D-de-energized. N-normal position. O-operated position. Rrearward. MF-rnoving forward. MR-moving rearward.

1 Shifting of this switch terminates stage.

The operator may terminate the dimpling operation (second stage) prematurely by releasing the foot switch 25 3 prior to the tripping of deflection switch 256, in which event the moving parts return to the Fig. 2 position. If the foot switch is released during the third or fourth stage, however, and left open, the cycle of operation will be completed in the usual manner.

In the above mentioned copending application, filed December 13, 1943, in the names of Howard R. Fischer and James A. Roberts, Serial No. 514,068, there are claims to the stroke adjuster (best shown in Fig. 3 herein) for regulating the return stroke of the plunger 23; claims to the automatic deflection control means and switch (best shown in Fig. 4 herein); claims to the anchoring means for rivet set holder [29 (which include anchoring rod I28, key E34- and plunger I31, best shown in Fig. 3 herein); and claims to the height adjusting means for spindle sleeve I53 (best shown in Fig. 6 herein). In a division of that application filed July 26, 1946, by the same applicants, Serial No. 686,406, there are claims to the solenoid valve (best shown in Fig. 8 herein) which. regulates the flow of the pressure fluid actuating the piston 43. In a copending application, filed January 15, 1945, by Howard R. Fischer individually, Serial No. 572,839, there are claims to the hold down sleeve and pad assembly, best shown in Fig. herein.

What is claimed is:

l. A dimpling and riveting press having a pair of mutually opposed jaws, a rivet set supported in association with one jaw and movable toward the other jaw, a recessed die supported by the latter or other jaw in alignment with said rivet set, said die being adapted to support a pair of metal sheets having a drilled hole therein in alignment with the die and set, the set being adapted to engage the head end of a tapered head rivet whose shank extends through the hole and into the recessed die, power operated means for moving the rivet set toward the die to dimple the sheet metal around the hole with the tapered rivet head acting as a punch extending into the die. means automatically operable upon the development of a predetermined pressure between the rivet set and die for reversing the stroke of the rivet set, a rivet upsetting pin engageable with the shank end of the rivet, means for moving the rivet upsetting pin into operative position within the die as the rivet set recedes from the die following a dimpling operation, means for locking said rivet upsetting pin in operative position, and means automatically operable in response to the operation of the locking means for driving the rivet set toward the rivet upsetting pin to upset the shank end of the rivet.

2. A dimpling and riveting press according to claim 1 which includes means responsive to a predetermined approach between the rivet set and the die during the upsetting stroke for reversing the stroke of the rivet set.

3. A dimpling and riveting press having a pair of mutually opposed jaws, a plunger mounted for movement in one jaw toward and from the other rivet set carried by said plunger and movable thereby toward the other jaw, a depressible hollow dimpling pad member mounted in association with the other jaw and having resilient means for returning the dimpling pad member from depressed to initial position, the latter member being adapted to support a work piece with a countersunk type head rivet extending through said work piece freely into said depressible dimpling pad member, said rivet set being conditioned upon movement of the plunger to depress the head of the rivet into the work piece to dimple the latter while it rests upon said dimpling pad member, a stop upon said dimpling pad member limiting the extent of the depression thereof by engaging with a portion upon said other jaw and thereby limiting the extent of the dimpling of said work piece by said rivet set, adjustable means upon said other jaw cooperating with said stop to determine the operated position of said dimpling pad member, a rivet support serving as a bucking member mounted for independent movement in proximity to said adjustable means, a shiftable member supported upon said other jaw having a portion capable in operated position thereof of obstructing the rivet support or bucl ing member against displacement from said operated position, means causing said bucking member to clear said shiftable member in initial idle position of the latter, shifting m ans controlling the position of movement of said shiftable member, and means causing the plunger to bring the rivet set down upon the head of the rivet once to dimple the work piece in idle position of said shiftable member and subsequently a second time in operated position of the shiftable member to upset the rivet upon the buckling member while the head thereof is seated in the dimpled portion of the work piece.

4. A dimpling and riveting press having a pair of mutually opposed jaws, a plunger mounted for movement in one jaw toward-the other jaw, a rivet set upon the plunger, fluid operated means for operating said plunger, a movable fluid control valve and a control means therefor, said valve controlling the supply of pressure fluid to said fluid operated means for causing controlled movement thereof, a rigid guide member mounted on the other jaw and projecting toward the plunger, a hollow dimpling pad member slidably surrounding said guide member, stop means on the guide member for limiting movement of the dimpling pad member toward said other jaw, a stationary spring housing attached to the latter jaw and containing a spring conditioned to resiliently maintain the dimpling pad member in normal raised position projecting toward the plunger and adapted to support a work piece with a countersunk flush type head rivet extending through said work piece into said dimpling pad member, an independently movable rivet bucking member slidably mounted in proximate association with said guide member and said dimpl'ing pad member, control means for shifting said rivet bucking member into effective bucking position 315 for the rivet and having means for supporting said bucking member in-said efiective position, automatic control means for first causing the fluid control valve to supply pressure fluid to drive the fluid operated means through a predetermined powerstroke and drive the plunger and thereby the rivet set down upon the :rivet head to dimplethe work piece when the latter rests on said dimpling pad member, said automatic control means being subsequently capable of causing said fluid control valve to be reversed for supplying pressure fluid to return said fluid operated means to initial position and thereby cause the plunger and rivet set to recede from the work piece, means cooperating with said automatic control means thereafter effective to cause the control means to shift the rivet bucking means to operated position and the fluid control valve to supply pressure fluid to drive the fluid operated means a second time during the operation cycle through a power stroke and drive said plunger and rivet set down upon the rivet and thereby eflect setting'of said rivet upon said bucking member with the head of the rivet seated in the dimpled portion of said work piece, and means causing the fluid operated means, fluid control valve, dimpling pad member, rivet bucking member, automatic control means, controlled means and the means cooperating with the automatic control means to return to initial position in readiness for a new cycle of operation,

5. A dimpling and riveting press including a press frame having a pair of mutually opposite jaws spaced apart, a plunger reciprocable in one jaw toward and from the other jaw and .having a rivet set mounted thereon, fluid operated means for reciprocating the plunger, depressible support means mounted on the other jaw for supporting a work piece having a countersunk flush type head rivetextending throughthe work piece into the support means, resilient means tending to restore the depressible support means to an initial raised position, a shiftable fluid control valve for controlling the flow of pressure fluid to, and exhaust of spent fluid from, the

fluid operated means, the fluid control valve in operated position being effective to cause pres sure fluid to drive the fluid operated means through a forward power stroke to bring the plunger and rivet set down toward the work piece on said depressi'ble support means in order to press the rivet set into said work piece to dimple the latter, said fluid control valve in initial position being effective to cause the pressure fluid to return said fluid operated means to initial rearward position, shifting means'for operating said fluid control valve, a rivet bucking membermovably mounted upon'said other jaw, a shiftable block capable in operated position of supporting the'bucking member in effective bucking position and 'in initial position being clear of the latter,'a second shifting means for shifting the block to operated position, stop means for limiting the depression imparted to the depressible support means to determine the depth to which the work piece is to be'dimpled, initial control means operable 'at will for initiating an operation cycle and cause the valve shifting means to shift the'fluid controlvalve to operated position and thereby causing the fluid operated means to drive the plunger and rivet set .down upon said. rivet head: and dimple the work piece, dimpling operated means becoming effective upon predetermined dimpling of the workpieceto cause thesecond shifting means to #16 effect shifting of said block to operated .position for supporting said bucking member in-the bucking position and said dimpling operated means also becoming efiective to neutralize operation of the flrst mentioned shifting means .to restore the fluid control valve to initial position and cause the plunger and rivet set to recede from the work piece, further means becoming'efi'ective upon shifting of said shiftable block towardoperated position to cause said first shifting-means again to shift the fluid control valve to operated position and thereby cause the rivet set tobe pressed down on the rivet the second time during the operation cycle while the bucking member is supported in said bucking position in'order to upset the rivet upon the latter with the head of said rivet seated in the dimpled portion of said work piece, and means becoming effective to terminate the operation cycle of the press'when said rivet is upset to predetermined extent and allow the press as a whole to be restored to initial condition in readiness for a new cycle of operation.

6. A dimpling press having a pair of mutually opposed jaws, a rivet set supported in association with one jaw and movable toward the other jaw, support means includin a hollow member mounted on said other jaw for supporting the work piece in operative position with a countersunk flush type head rivet inserted into a hole in the work piece and extending freely into the hollow member in order to provide clearance for the rivet head to be depressed into the work piece for dimpling the work piece While resting on the hollow member, and further support means efiective when said Work piece has been dimpled for supporting or bucking the rivet to cause the rivet set to exert pressure on the rivet head while it remains in the dimpled portion of the work piece and thereby upset said rivet upon said further support means, said rivet set having a hold down sleeve slidably supported thereon means limiting the movement of the hold down sleeve upon the rivet set and determining an initial position thereof in which said sleeve projects a predetermined distance beyond the end of said rivet set in order to engage against the work piece in advance of the rivet, a hold down pad of resilient material mounted on the rivet set, a stop on said rivet set for said pad and means disposed on the rivet set inefiective association with said hold down-pad and sleeve'to resiliently urge said hold down'sleeve toward its initial projecting position.

HOWARD R. FISCHER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,215,388 Butler Sept. 1'7, 1940 2,356,526 Mayer Aug. 22,1944 2,312,554 Jacques Mar. 2, 1943' 2,323,814 Lamb July 6, 1943 1,454,777 Walker May *8, 1923 767,205 Caughey Aug. 9, 1904 2,365,147 Sheller Dec. 12, 1944 2,230,518 Weinhold Feb.-4, 1941 2,063,691 Marchant Dec. 8, 1936 508,789 Vuillier Nov, 14, 1893 2,338,736 Peterson Jan. 11, 1944 FOREIGN PATENTS Number Country Date 487,152 GreatBritain June 13, 1938 Certificate of Correction Patent No. 2,442,949. June s; 1948.

HOWARD R. FISCHER It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows: Column 7, line 1, for Completing read Complementing; column 14, line 47, for buckling read bucking; column 16, line 61, list of references cited, for the name Butler read Butter line 67, for Sheller read Speller; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 21st day of September, A. D. 1948.

THOMAS F. MURPHY,

Assistant Uommissz'oner of Patents.- 

